Physical and chemical changes during the maturation of peaches (cv. Majestic)

Nonvolatile acids, sugars, and aroma volatiles from Majestic peaches were measured during maturation from 54 to 126 days after flowering. The highest levels of sucrose, lowest quinic acid levels, and second maximum malic/citric acid ratio occurred when mesocarp dry matter and seed reached their highest weight. Linalool, benzaldehyde, gamma-decalactone, and delta-decalactone increased significantly during the final stages of maturation with gamma-decalactone being the principal volatile compound. The increased levels of volatiles also closely paralleled seed and mesocarp growth. Pit lignification was complete about 50 days before the seed and mesocarp fully developed. Sucrose, quinic acid, malic/citric acid ratio, and major volatiles either singly or in combination appear to be useful indices for determining physiological maturity in the mesocarp and seed of Majestic peaches.